A standard motor-vehicle convertible top normally comprises a folding framework overlain by a flexible cover. The cover is comprised in turn of a waterproof outer layer, an intermediate sound- and heat-insulating layer, and an inner head liner layer and forms a roof, a rear panel extending from a rear edge of the roof, and often even side panels extending from side edges of the roof and rear panel. Strong but flexible bands or belts extend along the side edges of the roof and rear panel on an inside face of the cover. The framework is comprised of a plurality of transversely extending rigid struts or hoops whose ends are normally fixed to the bands and that typically are hidden between the inner and outer layers of the cover. This framework allows the top to move between a folded down position normally recessed behind the passenger compartment and an up position stretched over the passenger compartment and connected to the upper edge of the windshield.
U.S. Pat. No. 4,964,668 describes such a vehicle top where the outer layer is a skin stretched over the struts which support the inner layer. The outer layer rests virtually directly on the support struts so that there is no insulation at these locations. In addition the outer layer is formed of stitched-together panels which require meticulous treatment to avoid leakage.
German utility model 297 18 206 describes another top where mounting strips secure the support struts directly to the outer layer and the intermediate layer is pinched between the outer layer and the struts. The top structure is fairly complex, requiring many steps to secure the various parts together. In the finished top there is a thermal bridge between the outer layer and the struts formed by the mounting strips.
Further arrangements described in German utility models 69 445 15, 92 06 366, 92 09 122, and 9304 248 are similarly complex. Their assembly is a complex operation and they often leave sites for water or heat to get through the top. The support struts are secured to the outer layer from which the intermediate insulating layer is suspended, or the latter is itself mounted on the struts.